Recent hot weather in Britain has not concluded with thunderstorms, a pattern often associated with summer heat. While a brief hot spell ending in a thunderstorm is a familiar occurrence, this has not been the case in recent weeks.
Summer thunderstorms typically develop in an unstable atmosphere where hot air from the Earth's surface sits beneath cooler air. This allows warm, humid air to rise, condense, and form cumulonimbus clouds, which are classic storm clouds.
However, hot weather alone does not create this instability. Humidity is also essential for thunderstorm formation. During prolonged dry spells, limited evaporation at ground level results in rising air that is too dry to form clouds as it cools, preventing thunderstorms from developing and allowing heatwaves to persist.